As an example of a load driving device, a circuit which is described as a third conventional example in JP-A-H02-222040 is known. The circuit according to the third example is connected between a microcomputer, and a load and a ground. The circuit includes an nMOS that performs switching control of power supply application to the load and a relay that is disposed on an energizing path to the load. When an abnormality is detected, the circuit turns off the relay to stop energization to the load.
Because the relay, which stops energization to the load when an abnormality occurs, is disposed on the energizing path to the load, an electric current same as an electric current flowing into a nMOS, which drives the load in a normal operation, flows into the relay. Thus, the above-described circuit needs a relay that has a rating of the same degree as the nMOS.